bio chapt 2

What is the maximum number of covalent bonds that can form between a single carbon atom and 1 or more hydrogen atoms?

4

Distinguish between nonpolar covalent, polar covalent and ionic bonds.

A nonpolar covalent bond is a bond where electrons are shared equally between two atoms. A polar covalent bond is a chemical bond where the shared electrons spend more time closer to the nucleus of the more electronegative atom. In an ionic bond, the electrons are completely transferred from one atom to another rather than shared.

How do enzymes speed up chemical reactions?

By reducing activation energy

What elements make up a carbohydrate?

CHO

What are the parts that make up the lock-and-key model of enzyme function?

Enzyme and substrates and active site

A type of bond important in tying different parts of the same molecule together into a three-dimensional structure.

Hydrogen bond

How can enzymes be denatured?

Increase in temperature change in pH

Ionic bonds form between two atoms when:

One atom gives an electron to the other atom.

What type of bond holds amino acids together?

Peptide

Papain, an enzyme in papaya, breaks down polymers composed of amino acids. Which of the following substances does papain break down?

Proteins

Which statement most accurately describes the induced fit model of enzyme function?

Substrate binding slightly changes the shape of the enzyme.

With the use of a diagram or diagrams, explain why water molecules are: a. polar

The water molecule is polar because the shared electrons are closer to the oxygen atom rather than the hydrogen atoms.

Elements are unique substances that cannot be broken down into simpler substances by ordinary chemical means. T or F

True Elements cannot be broken down into other substances without changing their chemical properties.

A charged particle is correctly called an ion. T or F

True Ions are charged particles.

Enzymes are unchanged in a reaction; they can be reused, and are not needed in large quantities. T or F

True Three basic steps appear to be involved in enzyme action: 1. The enzyme's active site binds to the substrate(s) on which it acts, temporarily forming an enzyme-substrate complex. 2. The enzyme-substrate complex undergoes internal rearrangements that form the product(s). 3. The enzyme releases the product(s) of the reaction. Because enzymes are unchanged by their catalytic role and can act again and again, cells need only small amounts of each enzyme.

Ice floats on water

Water expands as it changes from a liquid to a solid, becoming less dense rather than more dense.

With the use of a diagram or diagrams, explain why water molecules are: b. capable of hydrogen bonding with 4 neighboring water molecules

With the use of a diagram or diagrams, explain why water molecules are: b. capable of hydrogen bonding with 4 neighboring water molecules The oxygen atom is charged as 2- .And the two hydrogen atoms are charged as 1+ each.Therefore the oxygen atom can attract two hydrogen atoms of other two water molecules and the two hydrogen atoms can attrat two oxygen atoms of another two water molecules

what does a catalyst do in a reaction

a catalyst lowers activation energy and increases the rate of reaction

which statement accurately explains one different between the lock and key model f enzyme function and the key you use to unlock a door

a door key is rigid, while enzymes can bend slightly to bind with substrates

what property allows water to travel from the roots of a plant to its leaves

adhesion

the building block for a protein

amino acids

Smallest particle of an element that retains its properties.

atom

an ________ is the smallest basic unit of matter

atom

A monomer represents a. 1 polymer b. compounds joined by water c. building blocks of polymers and other macromolecules d. one or more elements combined together

building blocks of polymers and other macromolecules

sugars and starches make up which group of carbon-based molecules

carbohydrates

cellulose, a glucose polymer found in plants, is tough and hard to chew, Why?

cellulose has a straight, rigid structure that helps support the plant

Breaking which type of bond would require the most energy?

covalent

a molecule is two more more atoms held together by _______ bonds

covalent

which bonds are stronger? covalent bonds or hydrogen bonds

covalent

Inside a water molecule the Oxygen and the 2 Hydrogens are joined by strong ___ a. covalent bonds b. hydrogen bonds c. ionic bonds d. savings bonds

covalent bonds

what type of bond forms when atoms share a pair of electrons

covalent bonds

a plant undergoing photosynthesis absorbs energy from sunlight and uses that energy to make sugars. The process absorbs more energy than it releases making it an __________ reaction

endothermic

whys is a high fever dangerous to enzymes

enzymes work best within a small temperature range, otherwise its hydrogen bonds may break apart

Lipids are types of ________ in food and are ___________ molecules because the electrons are shared evenly in covalent bonds. a. fats polar b. sugars polar c. sugars nonpolar d. fats nonpolar

fats / nonpolar

What is a buffer?

help maintain a pH equilibrium. It can release hydrogen or take hydrogen

hydrogen bonds are specific for 3 important properties of water

high specific heat cohesion adhesion

________ ions are released when an acid dissolves in water

hydrogen

water resists changes in temperature because ______- bonds give it an unusally high specific heat

hydrogen

water is a compound made up of

hydrogen and oxygen

how do hyrdogen bonds allow some insects to walk on water

hydrogen bonds form between slightly positive hydrogen atoms and slightly negative oxygen atoms, creating surface tension

A bond in which electrons are completely lost or gained by the atoms involved.

ionic bond

what is the pH of an acid

less than 7

polypeptide

linear polymer of amino acids, linked together by peptide bonds.

why would it be dangerous for a person to lose large amounts of water or blood

many molecules and ions cannot take part in chemical reactions unless dissolved in water

Smallest particle of a compound that still retains its properties.

molecule

what is each subunit of a macromolecule known as

monomer

The monomer for a carbohydrate

monosaccharides like glucose

A bond in which electrons are equally shared.

nonpolar covalent bond

Which represents a monomer of nucleic acids? a. monosaccharide b. nucleotide c. amino acid d. Polypeptide

nucleotide

monomers of nucleic acids are

nucleotides

Water is a __________ molecule because it does not share the electrons evenly within their covalent bonds. a. nonpolar b. healthy c. liquid d. Polar

polar

A bond in which electrons are NOT shared equally.

polar covalent bond

Carbohydrates form polymers such as: a. polysaccharides b. starch c. all are correct d. glycogen

polysaccharides, starch, glycogen

most enzymes are

proteins

ionic bonds are

strong attractions that are found in a compound

Carbohydrates are types of ________ and form ___________ molecules which can dissolve in water. a. fats nonpolar b. proteins polar c. sugar polar d. sugar nonpolar

sugar / polar

adhesion

the attractive force between 2 bodies of different substances that are in contact with each other (water sticks to other things)

cohesion

the force that holds molecules of a single material together (water sticks to itself)

The reason certain types of bugs can walk on water is because water has a high surface tension. T or F

true

Glucose is an example of a monosaccharide. T or F

true Glucose is a simple sugar

which type of fatty acid has at least one carbon-carbon bond

unsaturated fats

which type of fatty acid is found in most plant oild

unsaturated fatty acid